The present invention relates to an aqueous solution composition containing elcatonin as an active ingredient.
Elcatonin is a medicine having chemical name: 1-butyric acid-7-(L-2-aminobutyric acid)-26- o L-aspartic acid-27-L-valine-29-L-alanine-calcitonin (salmon) and is used for hypercalcemia or bone Paget's disease, or improvement of pain in osteoporosis. Activity of elcatonin is sometimes reduced owing to vigorous shaking when it is made to a preparation in the form of aqueous solution and it is not necessarily satisfactory as preparation which is to be stable against shaking.
Under such circumstance that mechanism of reduction in activity of aqueous solution of peptide owing to shaking has not been elucidated, the inventors have conducted intensive research in an attempt to maintain the present status of heat stability and light stability of elcatonin in the form of injections or further improve them and besides to maintain the present status of reduction of pain or further reduce the pain at injection. Furthermore, there has been reported that reduction in activity of aqueous solution of peptide caused by shaking can be prevented by adding a surface active agent, but there has been the problem in safety. Under the circumstances, the inventors have made further research in an attempt to solve the problem of reduction in activity without addition of surface active agent.
As a result, the inventors have found that an injection composition comprising an aqueous solution composition containing elcatonin as an active ingredient which has high stability of elcatonin against shaking can be obtained by adding a monocarboxy compound and/or its water-soluble salt in an amount of 0.05-20 mmol in molar concentration and adjusting pH to 5.0-6.5 and ionic strength to .mu.=0.01-0.5 and the resulting composition is no less better than conventional compositions in heat stability and light stability as an injection and in reduction of pain at injection.